patch-1.3.54 linux/fs/isofs/file.c

• Lines: 233
• Date: Thu Jan 4 20:26:24 1996
• Orig file: v1.3.53/linux/fs/isofs/file.c
• Orig date: Tue Dec 26 04:45:38 1995

diff -u --recursive --new-file v1.3.53/linux/fs/isofs/file.c linux/fs/isofs/file.c
@@ -15,27 +15,16 @@
 #include <linux/errno.h>
 #include <linux/stat.h>
 #include <linux/locks.h>
-
-#include <asm/segment.h>
-#include <asm/system.h>
-
-#define	NBUF	32
-
-#define MIN(a,b) (((a)<(b))?(a):(b))
-#define MAX(a,b) (((a)>(b))?(a):(b))
-
 #include <linux/fs.h>
 #include <linux/iso_fs.h>
 
-static int isofs_file_read(struct inode *, struct file *, char *, int);
-
 /*
  * We have mostly NULL's here: the current defaults are ok for
  * the isofs filesystem.
  */
 static struct file_operations isofs_file_operations = {
 	NULL,			/* lseek - default */
-	isofs_file_read,	/* read */
+	generic_file_read,	/* read */
 	NULL,			/* write */
 	NULL,			/* readdir - bad */
 	NULL,			/* select - default */
@@ -59,202 +48,9 @@
 	NULL,			/* rename */
 	NULL,			/* readlink */
 	NULL,			/* follow_link */
-	NULL,			/* readpage */
+	generic_readpage,	/* readpage */
 	NULL,			/* writepage */
 	isofs_bmap,		/* bmap */
 	NULL,	       		/* truncate */
 	NULL			/* permission */
 };
-
-/* This is a heuristic to determine if a file is text of binary.  If it
- * is text, then we translate all 0x0d characters to spaces.  If the 0x0d
- * character is not preceded or followed by a 0x0a, then we turn it into
- * a 0x0a.  A control-Z is also turned into a linefeed.
- */
-
-static inline void unixify_to_fs(char * outbuf, char * buffer, int chars,
-				 int mode)
-{
-	char outchar;
-
-	while(chars--){
-	  	outchar = *buffer;
-		if(outchar == 0x1a) outchar = 0x0a;
-		if(outchar == 0x0d){
-			if(mode == ISOFS_FILE_TEXT_M) outchar = 0x0a;
-			if(mode == ISOFS_FILE_TEXT) outchar = ' ';
-		}
-		put_user(outchar, outbuf++);
-		buffer++;
-	}
-}
-
-/*This function determines if a given file has a DOS-like text format or not*/
-
-static void isofs_determine_filetype(struct inode * inode)
-{
-	int block;
-	int result, i;
-	struct buffer_head * bh;
-	unsigned char * pnt;
-	
-	block = isofs_bmap(inode,0);
-	if (block && (bh = bread(inode->i_dev,block, ISOFS_BUFFER_SIZE(inode)))) {
-		pnt = (unsigned char *) bh->b_data;
-		result = ISOFS_FILE_TEXT_M;
-		for(i=0;i<(inode->i_size < ISOFS_BUFFER_SIZE(inode) ? inode->i_size : ISOFS_BUFFER_SIZE(inode));
-		    i++,pnt++){
-			if(*pnt & 0x80) {result = ISOFS_FILE_BINARY; break;};
-			if(*pnt >= 0x20 || *pnt == 0x1a) continue;
-			if(*pnt == 0x0a) {result = ISOFS_FILE_TEXT; continue;};
-			if(*pnt >= 0x9 && *pnt <= 0x0d) continue;
-			result = ISOFS_FILE_BINARY;
-			break;
-		}
-		brelse(bh);
-		inode->u.isofs_i.i_file_format = result;
-	}
-}
-
-static int isofs_file_read(struct inode * inode, struct file * filp, char * buf, int count)
-{
-	int read,left,chars;
-	int block, blocks, offset, total_blocks;
-	int bhrequest;
-	int ra_blocks, max_block, nextblock;
-	struct buffer_head ** bhb, ** bhe;
-	struct buffer_head * bhreq[NBUF];
-	struct buffer_head * buflist[NBUF];
-	
-	if (!inode) {
-		printk("isofs_file_read: inode = NULL\n");
-		return -EINVAL;
-	}
-	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))) {
-		printk("isofs_file_read: mode = %07o\n",inode->i_mode);
-		return -EINVAL;
-	}
-	if (inode->u.isofs_i.i_file_format == ISOFS_FILE_UNKNOWN)
-		isofs_determine_filetype(inode);
-	if (filp->f_pos > inode->i_size)
-		left = 0;
-	else
-		left = inode->i_size - filp->f_pos;
-	if (left > count)
-		left = count;
-	if (left <= 0)
-		return 0;
-	read = 0;
-	block = filp->f_pos >> ISOFS_BUFFER_BITS(inode);
-	offset = (inode->u.isofs_i.i_first_extent + filp->f_pos)
-	  & (ISOFS_BUFFER_SIZE(inode)-1);
-	blocks = (left + offset + ISOFS_BUFFER_SIZE(inode) - 1) / ISOFS_BUFFER_SIZE(inode);
-	bhb = bhe = buflist;
-
-	ra_blocks = read_ahead[MAJOR(inode->i_dev)] / (BLOCK_SIZE >> 9);
-	if(ra_blocks > blocks) blocks = ra_blocks;
-
-	/*
-	 * this is for stopping read ahead at EOF. It's  important for
-	 * reading PhotoCD's, because they have many small data tracks instead
-	 * of one big. And between two data-tracks are some unreadable sectors.
-	 * A read ahead after a EOF may try to read such an unreadable sector.
-	 *    kraxel@cs.tu-berlin.de (Gerd Knorr)
-	 */
-	total_blocks = (inode->i_size + (1 << ISOFS_BUFFER_BITS(inode)) - 1)
-	   >> ISOFS_BUFFER_BITS(inode);
-	if (block + blocks > total_blocks)
-		blocks = total_blocks - block;
-
-	max_block = (inode->i_size + BLOCK_SIZE - 1)/BLOCK_SIZE;
-	nextblock = -1;
-
-	/* We do this in a two stage process.  We first try and request
-	   as many blocks as we can, then we wait for the first one to
-	   complete, and then we try and wrap up as many as are actually
-	   done.  This routine is rather generic, in that it can be used
-	   in a filesystem by substituting the appropriate function in
-	   for getblk.
-
-	   This routine is optimized to make maximum use of the various
-	   buffers and caches. */
-
-	do {
-	        bhrequest = 0;
-		while (blocks) {
-		        int uptodate;
-			--blocks;
-			*bhb = getblk(inode->i_dev,isofs_bmap(inode, block++), ISOFS_BUFFER_SIZE(inode));
-			uptodate = 1;
-			if (*bhb && !buffer_uptodate(*bhb)) {
-			        uptodate = 0;
-			        bhreq[bhrequest++] = *bhb;
-			      };
-
-			if (++bhb == &buflist[NBUF])
-				bhb = buflist;
-
-			/* If the block we have on hand is uptodate, go ahead
-			   and complete processing. */
-			if(uptodate) break;
-
-			if (bhb == bhe)
-				break;
-		      }
-
-		/* Now request them all */
-		if (bhrequest)
-		  ll_rw_block(READ, bhrequest, bhreq);
-
-		do{ /* Finish off all I/O that has actually completed */
-		  if (*bhe) {/* test for valid buffer */
-		    wait_on_buffer(*bhe);
-		    if (!buffer_uptodate(*bhe)) {
-		      brelse(*bhe);
-		      if (++bhe == &buflist[NBUF])
-			bhe = buflist;
-		      left = 0;
-		      break;
-		    }
-		  }
-		  
-		  if (left < ISOFS_BUFFER_SIZE(inode) - offset)
-		    chars = left;
-		  else
-		    chars = ISOFS_BUFFER_SIZE(inode) - offset;
-		  filp->f_pos += chars;
-		  left -= chars;
-		  read += chars;
-		  if (*bhe) {
-		    if (inode->u.isofs_i.i_file_format == ISOFS_FILE_TEXT ||
-			inode->u.isofs_i.i_file_format == ISOFS_FILE_TEXT_M)
-		      unixify_to_fs(buf, offset+(*bhe)->b_data, chars, 
-				    inode->u.isofs_i.i_file_format);
-		    else
-		      memcpy_tofs(buf,offset+(*bhe)->b_data,chars);
-		    brelse(*bhe);
-		    buf += chars;
-		  } else {
-		    while (chars-->0)
-		      put_user(0,buf++);
-		  }
-		  offset = 0;
-		  if (++bhe == &buflist[NBUF])
-		    bhe = buflist;
-		} while( bhe != bhb && (*bhe == 0 || !buffer_locked(*bhe)) && 
-			(left > 0));
-	} while (left > 0);
-
-/* Release the read-ahead blocks */
-	while (bhe != bhb) {
-	  if (*bhe) brelse(*bhe);
-	  if (++bhe == &buflist[NBUF])
-	    bhe = buflist;
-	};
-
-	filp->f_reada = 1;
-
-	if (!read)
-		return -EIO;
-	return read;
-}